More and more people around the world are getting sick with two or more health conditions at the same time. For example, people are increasingly coping with two chronic non-infectious diseases, like hypertension and diabetes. Or they will have a chronic infectious disease like HIV and a chronic non-infectious disease like asthma.

The co-existing conditions could include diseases, disorders, illnesses or other chronic health problems. The concept of having two or more chronic health conditions at the same time is called multimorbidity.

Traditionally, developed countries have a high prevalence of non-communicable diseases – like hypertension – and due to this, a high rate of multimorbidity.

Now the tables seem to be turning. Due to the rise in the cases of non-communicable diseases in developing countries, there is an increasing emerging pattern of high levels of multimorbidity. This includes cases of hypertension which is now the most common co-morbid chronic non-communicable disease in the world.

The prevalence of non-communicable diseases is increasing at an alarming rate. In 2000, non-communicable diseases accounted for only 56% of the total disease burden. Scientists estimate that by 2020, they will account for almost 70% of the total disease burden in developing countries.

The increase has been driven by urbanisation and changing dietary and behavioural patterns with people eating more processed food and sugar and exercising less.

But alongside this, many developing nations, especially in Africa, have the additional burden of chronic infectious diseases.

Non-communicable diseases and chronic communicable diseases co-occur, and the risk factors, such as alcohol and tobacco use, associated with them are often shared. This further increases the likelihood of multimorbidity.

In Africa, the concern is that populations who are already socially and economically vulnerable also face the highest risk of multimorbidity. These include the elderly, people who have a lower socio-economic status and those who are not as educated. An intersectoral approach to address these vulnerable groups is needed. This remains challenging for developing health services in many African countries.

Affecting the patient and the system

The impact of multimorbidity is three-fold: it affects the patient, the health care provider and the health system as a whole.

Multimorbid patients have a decreased quality of life and tend to access health services more frequently. This often results in loss of potential income. And it places an extraordinary financial and psychological burden on the patient. The psychological burden often manifests as depression with mental health conditions frequently being associated with multimorbidity, which are often neglected or poorly managed.

More generally, the high self-management requirements and multiple drug prescriptions associated with multimorbidity can lead to poorer health outcomes for patients.

From the provider perspective, multimorbid patients are complex to treat. This can lead to increased workloads. In addition, they need an in-depth understanding of multiple drug and disease interactions. With each additional comorbidity consultation, time and individual patient cost increase dramatically.

But providers often find themselves in systems which are inadequately prepared to deal with this level of complexity due to their vertical nature. Vertical systems are based on the one disease model of care, which focuses on individual diseases, rather than holistic patient care.

Innovative models of integrated care are required to appropriately manage the multimorbid patient. This is a challenging task as integrated models need to be context specific. A “one size fits all” isn’t enough to address patients’ needs.

Tackling the problem

To tackle the problem, solutions need to focus on what’s causing multimorbidity. This means that policymakers must look beyond the health sector – they must engage with multiple sectors. This is necessary as most risk factors relating to multimorbidity are driven by factors that lie outside the health care system. Risk factors such as obesity, alcohol use and smoking can all be influenced by policies outside the health sector.

In South Africa, a well known example of this has been the reduction of secondary smoking as a result of a range of anti-smoking initiatives. These included using the media to run campaigns warning about the health risks of smoking, to limiting smoking areas in the hospitality industries alongside the establishment of an excise tax on tobacco products.

More recently, to address the rising burden of diabetes and associated risk factors, South Africa has proposed a tax on sugar-sweetened beverages. A similar tax was successful in reducing the consumption of sugar-sweetened beverages in Mexico.

One of the challenges in creating these policies lies in opposing powerful industry actors whose interests don’t lie with health issues, but with making profits. This requires advocacy from several key public health role players such as academics, civil society, and governmental departments.

Next steps

In Africa, multimorbidity will impose increasing strain on vulnerable people and already stretched health systems.

A structured collaborative approach is needed to manage the problem. This should include developing a good understanding of Africa’s unique patterns of multimorbidity, its causes, and focus on prevention.